Thytronic NA11 User Manual

82
82
NA11 - Manual - 02 - 2009
FUNCTION CHARACTERISTICS
Frequency tracking
Within the frequency range 45...66 Hz, a frequency tracking algorithm adjusts the currents sampling
frequency, so as to keep the number of samples in any given period constant.
With 24 samples for periods the sampling rate is 1.08kHz with f=45Hz and 1.58kHz with f=66Hz.
The frequency measure is based on the largest phase voltage or current.
If the larger phase input current is lower than 25% I
n
and the larger phase input voltage is lower
than 1.5% E
n
the sampling frequency is fi xed to f
n
(50 or 60 Hz).
If the line frequency is outside the locking range
,
the sampling frequency is fi xed to the lower or
upper value
(45 or 55 Hz with f
n
= 50 Hz, 54 or 66 Hz with f
n
= 66 Hz)).
All protective elements are always operative; accuracy is guaranteed inside locked frequency
band.
•
•
IF.ai
Frequency tracking
0.25 I
n
- 1% E
n
0.25 I
n
- 1% E
n
30 45 6055
f (Hz)
50 Hz (0 Hz)
f
n
50 Hz
Displayed value
Locked frequency
Locked frequency (Displayed value)
Displayed value
Locked frequency
Locked frequency (Displayed value)
Max I
L1...L3
Max U
L1...L3
Max U
L1...L3
I
L1
I
L2
I
L3
Frequency tracking
f
Max I
L1...L3
> 0.25 I
n
30 Hz
45 Hz
60 Hz
55 Hz
40 54 7066
f (Hz)
60 Hz (0 Hz)
f
n
60 Hz
Max I
L1...L3
40 Hz
54 Hz
70 Hz
66Hz

Thytronic NA11 Specifications

General

Brand	Thytronic
Model	NA11
Category	Relays
Language	English